Feed gas supply units for fuel cell systems generally include a control unit and a drive unit. The control unit includes a controller housed in an air-cooled housing. The motor unit includes cooling fluid channels and is cooled by a cooling fluid such as water.
These traditional feed gas supply units retain several disadvantages. These disadvantages are particularly applicable to implementation of the feed gas supply units in automotive applications. For instance, the control unit reaches undesired temperatures within the warm motor room of the automobile which can encounter temperature increases up to 125° C. In particular, there is insufficient air flow within the motor room to flow through cooling fins of the control unit and adequately cool the control unit. As a result, electric losses and the chance of control unit failure increase.
With regard to the drive unit, the bearings of the motor unit are not adequately cooled. Operation of the bearings at undesired temperatures results in an increase in the chance of bearing failure. Bearing failure can result in malfunction of the feed gas supply unit or complete failure of the feed gas supply unit.
Further, compression of the feed gas within the feed gas supply unit results in a volume decrease and a corresponding temperature and pressure increase. The feed gas density directly effects regulation of the fuel cell system. Regulation of the fuel cell system becomes more difficult because of the increased density of the feed gas.